BMW stop/start

[shiniy4]

Hi
I’ve got the stop start warning light coming on.
I’ve done the diagnostic on it and the fault codes are:
43A2 starter lockout delay
4CB4 msa start enabler line to cas
CD87 unknown fault
4C18 terminal 15 0x130
4AFA brake vacuum sensor
4AFB brake vacuum sensor

How has all the above happened? I can drive my car but is it safe to do so?

[helix402]

1. Phone your local BMW dealer and ask if there are any outstanding Quality Enhancements or recalls on your car

2. Get battery tested with battery tester, not voltmeter.

If 1 and or 2 don’t lead to the cause of the problem-time to pay for some diagnosis.

[Elliot2000]

shiniy4 said:

Hi
I’ve got the stop start warning light coming on.
I’ve done the diagnostic on it and the fault codes are:
43A2 starter lockout delay
4CB4 msa start enabler line to cas
CD87 unknown fault
4C18 terminal 15 0x130
4AFA brake vacuum sensor
4AFB brake vacuum sensor

How has all the above happened? I can drive my car but is it safe to do so?

Some of them may be historic faults and nothing to worry about.

Your issue will be the brake vacuum sensor tho- sits near the bottom of the servo and just pushes is

[Elliot2000]

Start stop is not great for the engine tbh, it’s worth just disabling it - it causes more wear on the engine, tensioners and chains, starter motors, etc. And I remember when bmw first intorduced the efficient dynamics on their cars, which included lots of things and not just stop start and they told us stop start on accounted for 2% of the efficiency gains. The active flaps in the grills and the smart charging where it charges the battery flat out when your on the overrun or when braking has much more of an effect

[anonymous-user]

Before you do anything charge the battery. If the fault is still there, have the battery checked.

My 530 gave me a list of faults, including low oil pressure, do not drive, after being stood for a few weeks when about 3yo.

Charged the battery, cleared the faults and it was fine ever after.

[shiniy4]

Hi
I have had my safety recall items done just before Xmas and then this stop start light came on a few days later. I have taken it back to BMW yesterday and asked them to check if the fault isn't related to the safety recall and they said no, it's the brake vacuum sensor.

I'm taking it to a local BMW specialist during the week I'll ask them to check battery

[shiniy4]

Elliot2000 said:

Start stop is not great for the engine tbh, it’s worth just disabling it - it causes more wear on the engine, tensioners and chains, starter motors, etc. And I remember when bmw first intorduced the efficient dynamics on their cars, which included lots of things and not just stop start and they told us stop start on accounted for 2% of the efficiency gains. The active flaps in the grills and the smart charging where it charges the battery flat out when your on the overrun or when braking has much more of an effect

How to do disable the stop start?

[Pica-Pica]

shiniy4 said:

Elliot2000 said:

Start stop is not great for the engine tbh, it’s worth just disabling it - it causes more wear on the engine, tensioners and chains, starter motors, etc. And I remember when bmw first intorduced the efficient dynamics on their cars, which included lots of things and not just stop start and they told us stop start on accounted for 2% of the efficiency gains. The active flaps in the grills and the smart charging where it charges the battery flat out when your on the overrun or when braking has much more of an effect

How to do disable the stop start?

You can temporarily disable it by the button above the stop/start button. That will turn it off for the duration of that drive. It automatically reverts to stop/start on a new journey.

[FurtiveFreddy]

shiniy4 said:

How to do disable the stop start?

Get a Carly and code it off.

[Pica-Pica]

FurtiveFreddy said:

shiniy4 said:

How to do disable the stop start?

Get a Carly and code it off.

Does that turn it off completely, or does it just make it off from each new start. That is, can you override it to bring stop/start function back into play by pressing the off button?

[FurtiveFreddy]

Pica-Pica said:

Does that turn it off completely, or does it just make it off from each new start. That is, can you override it to bring stop/start function back into play by pressing the off button?

Yes, it actually changes it so that stop/start starts in the last state.

That means that if you want your key profile to have it disabled when you start, that will work but if someone else prefers to have it on when they start, their key profile will mean it will be enabled when they start. (Hope I explained that clearly...)

Edited by FurtiveFreddy on Saturday 5th January 12:44

[4rephill]

Elliot2000 said:

Start stop is not great for the engine tbh, it’s worth just disabling it - it causes more wear on the engine, tensioners and chains, starter motors, etc.

A quick Google brings up the following information:

From: https://www.autocar.co.uk/car-news/new-cars/stop-s... :

A conventional electric starter motor works by engaging a small pinion gear with a large ‘ring’ gear fitted around the outside of the engine flywheel.

The latest stop-start technology looks much the same but the motors are more powerful, faster acting and more robust. Some are designated ‘TS’ for ‘tandem solenoid’ and designed to cope more smoothly with scenarios where the engine is about to stop and then the driver accelerates again.


From: https://practicalmotoring.com.au/car-advice/myth-b... :

Practical Motoring spoke with the technical boss at a leading car maker who said that stop-start doesn’t cause additional wear and tear on an engine but that the owner must adhere to the recommended service schedule and use the manufacturer’s recommended oil. “Using cheaper oils can cause more damage to your car’s engine than anything else,” he told Practical Motoring. “Operational stop-start causes no wear and tear at all; wear and tear at cold start-up is a thing, though,” he said.


https://www.greencarreports.com/news/1109687_dont-...

Along with numerous other automotive industry sites that state that the stop/start systems are designed to reduce/eliminate the possibility of additional wear to engine components.

So can you produce evidence to support your claim that stop/start systems do increase wear to engine components?, or is your statement based only on your personal thoughts, with no supporting evidence?

[Elliot2000]

4rephill said:

A quick Google brings up the following information:

From: https://www.autocar.co.uk/car-news/new-cars/stop-s... :

A conventional electric starter motor works by engaging a small pinion gear with a large ‘ring’ gear fitted around the outside of the engine flywheel.

The latest stop-start technology looks much the same but the motors are more powerful, faster acting and more robust. Some are designated ‘TS’ for ‘tandem solenoid’ and designed to cope more smoothly with scenarios where the engine is about to stop and then the driver accelerates again.


From: https://practicalmotoring.com.au/car-advice/myth-b... :

Practical Motoring spoke with the technical boss at a leading car maker who said that stop-start doesn’t cause additional wear and tear on an engine but that the owner must adhere to the recommended service schedule and use the manufacturer’s recommended oil. “Using cheaper oils can cause more damage to your car’s engine than anything else,” he told Practical Motoring. “Operational stop-start causes no wear and tear at all; wear and tear at cold start-up is a thing, though,” he said.


https://www.greencarreports.com/news/1109687_dont-...

Along with numerous other automotive industry sites that state that the stop/start systems are designed to reduce/eliminate the possibility of additional wear to engine components.

So can you produce evidence to support your claim that stop/start systems do increase wear to engine components?, or is your statement based only on your personal thoughts, with no supporting evidence?

My evidence is working in the industry for well over a decade fixing the things day in day out and a good knowledge of how the systems work. The starter motors they used on the original cars were no different to non start stop cars.

With an idling engine the oil pressure is kept steady and is being pumped to all components that require it, cooling and lubricating as it should. If u can imagine a car being driven hard and then coming to a stop - last thing I want to do is stop the oil circulating as it’s needed to cool the components. With start stop you are continually allowing oil pressure to drop to nothing and then have to crank the engine means oil then has to be raised back up to pressure which is not instant. This also means everytime ur restarting the engine the chain tensioners are being used with just spring pressure which is not good for the chain gear as it causes extra rattling. On the diesels that I worked on with this system - they were using mechanical water pumps which only run when engine runs which means cooling system is less efficient or coolant stops flowing around the head as soon as it cuts out.

Now stop start is not the end of the world, but it’s good for short term benefit, and it’s only a very small benefit - as I said before, less than 5% of efficiency gains from the efficient dynamics systems- with that you are putting extra wear on lots of other systems but feel free to use it

Plus big shock - major motor manufacturer that is trying to sell these cars claims it doesn’t cause any wear.

The green car articles is only looking at the starter motor , and not the engine, and in their own report American EPA cycles found only negligible mpg savings (0.1mpg)

nice articles you found - how about speaking to an engineer?

Edited by Elliot2000 on Saturday 5th January 17:52

[Pica-Pica]

Elliot2000 said:

4rephill said:

A quick Google brings up the following information:

From: https://www.autocar.co.uk/car-news/new-cars/stop-s... :

A conventional electric starter motor works by engaging a small pinion gear with a large ‘ring’ gear fitted around the outside of the engine flywheel.

The latest stop-start technology looks much the same but the motors are more powerful, faster acting and more robust. Some are designated ‘TS’ for ‘tandem solenoid’ and designed to cope more smoothly with scenarios where the engine is about to stop and then the driver accelerates again.


From: https://practicalmotoring.com.au/car-advice/myth-b... :

Practical Motoring spoke with the technical boss at a leading car maker who said that stop-start doesn’t cause additional wear and tear on an engine but that the owner must adhere to the recommended service schedule and use the manufacturer’s recommended oil. “Using cheaper oils can cause more damage to your car’s engine than anything else,” he told Practical Motoring. “Operational stop-start causes no wear and tear at all; wear and tear at cold start-up is a thing, though,” he said.


https://www.greencarreports.com/news/1109687_dont-...

Along with numerous other automotive industry sites that state that the stop/start systems are designed to reduce/eliminate the possibility of additional wear to engine components.

So can you produce evidence to support your claim that stop/start systems do increase wear to engine components?, or is your statement based only on your personal thoughts, with no supporting evidence?

My evidence is working in the industry for well over a decade fixing the things day in day out and a good knowledge of how the systems work. The starter motors they used on the original cars were no different to non start stop cars.

With an idling engine the oil pressure is kept steady and is being pumped to all components that require it, cooling and lubricating as it should. If u can imagine a car being driven hard and then coming to a stop - last thing I want to do is stop the oil circulating as it’s needed to cool the components. With start stop you are continually allowing oil pressure to drop to nothing and then have to crank the engine means oil then has to be raised back up to pressure which is not instant. This also means everytime ur restarting the engine the chain tensioners are being used with just spring pressure which is not good for the chain gear as it causes extra rattling. On the diesels that I worked on with this system - they were using mechanical water pumps which only run when engine runs which means cooling system is less efficient or coolant stops flowing around the head as soon as it cuts out.

Now stop start is not the end of the world, but it’s good for short term benefit, and it’s only a very small benefit - as I said before, less than 5% of efficiency gains from the efficient dynamics systems- with that you are putting extra wear on lots of other systems but feel free to use it

Plus big shock - major motor manufacturer that is trying to sell these cars claims it doesn’t cause any wear.

The green car articles is only looking at the starter motor , and not the engine, and in their own report American EPA cycles found only negligible mpg savings (0.1mpg)

nice articles you found - how about speaking to an engineer?

Edited by Elliot2000 on Saturday 5th January 17:52

..so, you have seen test sign-off documents that verify/deny all that?

[Elliot2000]

Pica-Pica said:

..so, you have seen test sign-off documents that verify/deny all that?

Troll?

Which test documents might u be talking about? The articles linked which have done no testing from what I can see? or the failures and faults that I have seen myself, stripped down and repaired myself, written reports on myself which have been accepted by the manufacturer each time to allow warranty repairs to be approved every time? Let alone colleagues who have done the same, or speaking to the trainers, the warranty auditors or people with more knowledge and experience than myself within the industry?

I think I will stick with troll, or maybe your just an idiot- plenty of both on here these days

[Elliot2000]

4rephill said:

A quick Google brings up the following information:

From: https://www.autocar.co.uk/car-news/new-cars/stop-s... :

?

Did you actually read this article? It goes on to talk about the challenges of trying to reduce the extra wear on the engine by trying to use different bearing coatings and different oils.

[Mr Tidy]

Elliot2000 said:

Start stop is not great for the engine tbh, it’s worth just disabling it - it causes more wear on the engine, tensioners and chains, starter motors, etc. And I remember when bmw first intorduced the efficient dynamics on their cars, which included lots of things and not just stop start and they told us stop start on accounted for 2% of the efficiency gains. The active flaps in the grills and the smart charging where it charges the battery flat out when your on the overrun or when braking has much more of an effect

Well I'm definitely not a fan of stop/start!

In 2008 I bought a pre-reg 57 plate 123d that had it. The coded AGM battery managed just over 4 years, and cost just over £250 to replace by a BMW Indy (Sytner quoted over £300). The starter motor just got past 6 years to 77K miles and cost £600+ at Sytner! I turned stop/start off every time I used it after that - thankfully both turbos managed to survive. But bearing in mind the N47 cam-chain issues I sold it in 2014 with 81K miles, although it's MOT expired in October 2018 so it looks like I got lucky!

By comparison my 56 plate Z4 with a normal battery needed a new one in December 2017 that didn't need coding after 80K miles, and it cost about £100!

My 123d had the active flaps, but no temperature gauge - you aren't going to get much warning if they don't work!

I'd happily trade 2% efficiency for some reliability - a 2% saving on fuel even on 80K+ miles can't be more than the £850 I spent on a coded AGM battery and starter motor!

Before my 123d I had an E46 320td with none of that nonsense! Over 40K+ miles it averaged 47.8 mpg, yet over 80K+ miles my 123d only managed 48.7 mpg - that's hardly progress IMHO.

Personally I'd avoid it like the plague - failing that get it coded off or just turn it off - it may save a few quid on road tax but it's cr*p IME!